By now most of you have seen the DIY solar generator project intro and project build. I specified enough battery storage to power a QRO field station for roughly 24 hours of operation, without solar power. As with all my portable power projects, the battery storage is augmented by solar panels at home, and in the field. So it’s fair to say “a solar generator without the ability to provide clean, renewable, energy on its own, is not really a solar generator”. This one is!

Enter the PowerFilm R28 from the Rollable series.

Current panels

At the moment I have three sets of panels ranging from rigid panels on the tower, large but lightweight foldable panels for man portable field communications, and lightweight high-speed low-drag panels for thru-hiking.

120w FM16-7200 – Currently the 120 watt PF folding panel, is the Workhorse of my portable power capabilities. It can generate 120 Watts or 7.2 amps in a man-portable package. It can withstand light rain, snow, the cold and most things we can throw at it.

2x 20w FM16-1200 – The 20 watt PF panels are the core of my qrp or low-power, man-portable ops. These panels are also good for light rain, snow, and most things we can throw at them.

I’ve been extremely happy with the performance of the 120w and 20w folding PF panels, and wouldn’t change them for the world.

The Rollable series

The difference between the foldable and rollable series is being completely sealed, waterproof, and practically submersible. I chose the 2x 28 Watt rollable solar panel after experiencing torrential rains, during the X days off grid series. The foldable handled it with a little drying off, airing out after the rains. Still, I wanted to be able to deploy my solar panels outside the tipi tent shelter, without worrying about turning in for the night, only to wake up in torrential rains, with my solar panels waterlogged. With the rollable series I can set them up and leave them up, whatever weather comes. I can deploy them in a swamp, off the sides of my inflatable, draped over the hiking trailer, or mounted on top of our Subaru Outback, without having to care about the weather. Think of it this way, I deploy them when I get on site, I only pack them up when I am leaving the site, regardless of how many days that’s been.

Why so low wattage?

During the X days off grid trip to Lapland, I brought my solar panels into the tipi tent at night, and put them back out in the morning. I did this so I could have a good night sleep without worrying about waterlogged solar panels. I believe if I’m able to leave a solar panel out constantly, I can start charging up my portable power solution earlier, even before I wake up, also much later into the evening.

The next point is the amount of power I’m running in the field. Traditionally I’m using 30 watts of power on transmit with digital modes. I try to limit that to no more than 25% TX, 75% RX. There is a caveat. I have observed the phenomenon of needing more transmit power, the further north in latitude I go. So the further north my Expeditions take me, the more output power I may need, even though the same distance on East-West longitude, would not require any additional tx power. With that said I was using js8 during the X days off grid series trip to Lapland. The system was in automatic mode, Auto responding to stations which queried my station remotely. Even though that functionality was enabled, I didn’t run out of power until the morning of the third day in the field. If I’m more conservative with my communications, I believe this 56 watts of solar panels to be enough to power the station. I can always augment the solar panels with the 120 watt folding panel if need be.

Portable solar panels

Lets talk about emergency communications and Communications for preparedness. I always use the example of Puerto Rico and the ARES/ARRL nightmare deployment there. Puerto Rico showed us that being deployed sometimes means getting off our butts and Hiking 20 30 40 clicks down the road to our operating location. It also means we might need to hump our Communications and portable power gear. There is simply no chance we’re going to backpack carry our comms gear, our own kit, and a gasoline or diesel generator in our backpacks. That’s just not going to happen! Of course Puerto Rico was an extreme example, but there were other examples in the Caribbean, supporting the idea of deploying completely self-contained man-portable stations. All of these examples came as a result of Hurricane Maria. Backpack portable, portable power is critically important to Communications for preparedness, and emergency communications deployments for Disaster Recovery. We can’t always assume there’s going to be a gasoline or diesel generator there waiting for us. In a true grid down scenario, the logistics machine has probably failed, and the only things you can rely on, is the gear we bring with us. That includes portable power! Naturally if we’re operating out of an Overland rig, there’s room to carry all sorts of rigid solar panels, suitcase solar panels, generators, … along with lead acid batteries to store our energy. When the roads are blocked and we need to carry our gear, lightweight portable power becomes a necessity. The perceived cost savings of moveable not portable gear won’t matter if we have to leave our gear behind. Now the “cost saving” are costing time, and potentially lives.

Final thoughts

As I said earlier in this article, the foldable PF panels have been amazing, I wouldn’t change them for anything. With that said you might be wondering why the heck would I include the rollable series in my toolbox. Well last year with the X days off grid series, I learned very much about portable solar power during a deployment. Sometimes we mistakenly believe if it’s raining we can’t make power from our solar panels, but that isn’t true. As long as there’s some daylight we’re going to generate power. The more sunlight we have, the more power we generate. Amorphous thin-film panels do a pretty good job of generating power in low light conditions. Add an MPPT charge controller and we are cooking with fire. Seriously though, rather than only deploying my solar panels in perfect conditions, I want to be able to deploy solar panels any time of the day or night, in any conditions. I say this because I believe it’s better to get some incoming solar energy all the time, as opposed to getting good solar energy, only when perfect conditions exist.

Our solar panels need to go where we go, they need to handle what we handle. Sometimes they need to handle even more.